| 1. |
- Hedeland, Ylva, 1974-, et al.
(författare)
-
Hemolysis interference in 10 coagulation assays on an instrument with viscosity-based, chromogenic, and turbidimetric clot detection
- 2020
-
Ingår i: International Journal of Laboratory Hematology. - : Wiley. - 1751-5521 .- 1751-553X. ; 42:3, s. 341-349
-
Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Hemolysate in plasma samples from patients may cause misleading results in coagulation assays. Even though modern coagulation instruments often are equipped with modules that can detect hemolysis, icterus, and lipemia (HIL), studies that report the influence of these interferences are still limited. The present paper focuses on the influence of hemolysis on 10 coagulation assays.METHODS: Artificial hemolysis was created by freezing/thawing, and the hemolysates generated were added to pools of patient plasma. Pathological and normal levels were pooled separately. These spiked samples were analyzed on a STA R Max 2 instrument. The coagulation assays evaluated utilize clot, chromogenic, or immunoturbidimetric detection.RESULTS: Four of the evaluated assays were not influenced by hemolysis: fibrinogen, von Willebrand factor antigen, activated partial thromboplastin time, and factor VIII. Interestingly, normal and slightly elevated prothrombin time (INR < 2.0) was insensitive to hemolysis, whereas samples with a high INR (≥2.0) exhibited falsely high readings. The assays for antithrombin and fibrin D-dimer displayed an intermediate sensitivity to hemolysis. The most sensitive assay turned out to be anti-Xa, followed by protein C and protein S. For the anti-Xa assay, the results are decreased by 10% already at 0.5 g/L hemoglobin.CONCLUSION: The present study shows that hemolysis affects several of commonly used coagulation assays. Since the sensitivity for hemolysis is dependent on the brand of the assay as well as the instrument and principle of measurement, it is necessary to evaluate the influence of each specific combination.
|
|
| 2. |
- Helmersson-Karlqvist, Johanna, et al.
(författare)
-
Association of Test Results for 33 Frequently Used Laboratory Tests with Body Mass Index (BMI)
- 2020
-
Ingår i: CLINICAL AND EXPERIMENTAL INVESTIGATIONS. - Lewes. ; 1:1, s. 2-4
-
Tidskriftsartikel (refereegranskat)abstract
- Once considered a problem only for high-income countries, obesity rates are now rising worldwide. When evaluating test results from obese patients it is important to be aware of the effect of obesity on individual laboratory test results. The aim of the present study was to study the association between body mass index (BMI) and a group of frequently requested laboratory tests to evaluate which of these analytes that are affected by BMI. We analyzed the association between body mass index (BMI) and Alanine aminotransaminase (ALT), Albumin, Alkaline phosphatase, Pancreatic amylase, Apolipoprotein A1, Apolipoprotein B, Apolipoprotein B/Apolipoprotein A1 ratio, Aspartate aminotransferase (AST), AST/ALT ratio, Bilirubin, Calcium, Calprotectin, Cholesterol, HDL-cholesterol, Creatinine kinase (CK), Creatinine, C-reactive protein, Cystatin C, Gamma-glutamyl transferase (GGT), Iron, Iron saturation, Lactate dehydrogenase (LDH), Magnesium, Phosphate, Transferrin, Triglycerides, Urate, Urea, Zink, Hemoglobin, Platelet count and White blood cell count in an 80-year old population (n=531, 266 females and 265 males). There were significant Spearman rank associations between BMI and laboratory test results for several of the studied markers in both females and males. The strongest associations with BMI were noted for ALT, Apolipoprotein A1, HDL-cholesterol, Hemoglobin, CRP, Cystatin C, Triglycerides and Urate. In conclusion, several of the most frequently used laboratory markers are significantly associated with BMI. To be able to correctly interpret a test result it is important to be aware of the effects of BMI on the test results.
|
|
| 3. |
- Lundgren, Morgan, et al.
(författare)
-
Interlaboratory variation for NT-proBNP among Swedish laboratories in an external quality program 2011-2021
- 2023
-
Ingår i: Clinical Chemistry and Laboratory Medicine. - : Walter de Gruyter. - 1434-6621 .- 1437-4331. ; 61:9, s. 1643-1651
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: NT-proBNP is frequently used for ruling out heart failure. Different cut-offs are used depending on the clinical context, e.g. an acute or chronic condition. Medical decision limits have been suggested at 125 and 300 ng/L or 400 ng/L in international guidelines. However, there is limited standardization between NT-proBNP methods and using the same blood sample might cause different treatment of patients.Methods: Data from the external quality assessment program for NT-proBNP from Equalis, Sweden, were extracted for the period 2011-2021, and categorized according to manufacturer. Manufacturer median NT-proBNP values were compared to total median values. CV% was calculated for each manufacturer and in comparison to different levels of NT-proBNP.Results: Roche was the most common method, and its median results were closest to the median consensus results. When looking at the total CV at NT-proBNP levels in the range of 0-500 ng/L, the total CV varied from 4 to 27%. During 2019-2021, Siemens (Immulite, Centaur, Atellica) yielded results 16-20% above the consensus median depending on sample level. Similarly, Abbott was 5-7% above, while Roche and Siemens Stratus were 1% respectively 6-10% below the consensus median.Conclusions: The introduction of new manufacturers and methods in 2017 have caused the agreement between manufacturers to decline. This highlights the need for a common calibrator and reference materials, particularly since medical decision limits in guidelines, e.g. European Society of Cardiology 2021, which are mostly based on Roche methods, do not take these method differences into account.
|
|
| 4. |
- Malmgren, Linnea, et al.
(författare)
-
The complexity of kidney disease and diagnosing it - Cystatin C, selective glomerular hypofiltration syndromes and proteome regulation.
- 2023
-
Ingår i: Journal of Internal Medicine. - : John Wiley & Sons. - 0954-6820 .- 1365-2796. ; 293:3, s. 293-308
-
Tidskriftsartikel (refereegranskat)abstract
- Estimation of kidney function is often part of daily clinical practice, mostly done by using the endogenous GFR-markers creatinine or cystatin C. A recommendation to use both markers in parallel in 2010 has resulted in new knowledge concerning the pathophysiology of kidney disorders by identification of a new set of kidney disorders, selective glomerular hypofiltration syndromes. These syndromes, connected to strong increases in mortality and morbidity, are characterised by a selective reduction in the glomerular filtration of 5-30 kDa molecules, such as cystatin C, compared to the filtration of small molecules < 1kDa dominating the glomerular filtrate e.g., water, urea, creatinine. At least two types of such disorders, shrunken or elongated pore syndrome, are possible according to the pore model for glomerular filtration. Selective glomerular hypofiltration syndromes are prevalent in investigated populations, and patients with these syndromes often display normal measured GFR or creatinine-based GFR-estimates. The syndromes are characterised by proteomic changes promoting the development of atherosclerosis, indicating antibodies and specific receptor-blocking substances as possible new treatment modalities. Presently, the KDIGO guidelines for diagnosing kidney disorders do not recommend cystatin C as a general marker of kidney function and will therefore not allow the identification of a considerable number of patients with selective glomerular hypofiltration syndromes. Furthermore, as cystatin C is uninfluenced by muscle mass, diet or variations in tubular secretion and cystatin C-based GFR-estimation equations do not require controversial race or sex terms, it is obvious that cystatin C should be a part of future KDIGO guidelines.
|
|
| 5. |
- Nalsen, C., et al.
(författare)
-
Vitamin D status in children and adults in Sweden: dietary intake and 25-hydroxyvitamin D concentrations in children aged 10-12 years and adults aged 18-80 years
- 2020
-
Ingår i: Journal of Nutritional Science. - : Cambridge University Press (CUP). - 2048-6790. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- The study aimed to estimate vitamin D intake and plasma/serum 25-hydroxyvitamin D (25(OH)D) concentrations, investigate determinants of 25(OH)D concentrations and compare two 25(OH)D assays. We conducted two nationwide cross-sectional studies in Sweden with 206 school children aged 10-12 years and 1797 adults aged 18-80 years (n 268 provided blood samples). A web-based dietary record was used to assess dietary intake. Plasma/serum 25 (OH)D was analysed by liquid chromatography-mass spectrometry (LC-MS) and immunoassay in adults and LC-MS/MS in children. Most participants reported a vitamin D intake below the average requirement (AR), 16 % of children and 33 % of adults met the AR (7.5 mu g). In adults, plasma 25 (OH)D below 30 and 50 nmol/l were found in 1 and 18 % of participants during the summer period and in 9 and 40 % of participants during the winter period, respectively. In children, serum 25(OH)D below 30 and 50 nmol/l were found in 5 and 42 % of participants (samples collected March-May), respectively. Higher 25(OH)D concentrations were associated with the summer season, vacations in sunny locations (adults), and dietary intake of vitamin D and use of vitamin D supplements, while lower concentrations were associated with a higher BMI and an origin outside of Europe. Concentrations of 25 (OH)D were lower using the immunoassay than with the LC-MS assay, but associations with dietary factors and seasonal variability were similar. In conclusion, vitamin D intake was lower than the AR, especially in children. The 25(OH)D concentrations were low in many participants, but few participants had a concentration below 30 nmol/l.
|
|
| 6. |
- Ridefelt, Peter, et al.
(författare)
-
Pediatric reference intervals for serum folate and cobalamin based on a European population without exposure to folic acid fortification.
- 2024
-
Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - 0036-5513 .- 1502-7686. ; , s. 1-5
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to define pediatric reference intervals for serum cobalamin and folate utilizing data generated from a population not exposed to food fortified with folic acid. Folate and cobalamin results analyzed by electrochemiluminescence immunoassay (Roche Cobas) were obtained from 2375 children (2 months to 17.99 years of age). The serum samples were collected between 2011 and 2015 as part of the LIFE (Leipzig Research Centre for Civilization Diseases) Child cohort study in Germany, where folic acid fortification of food is not mandated. These results were used to generate age- and gender-specific reference intervals presented as non-parametric 2.5 and 97.5 percentiles. Because of a subsequent restandardisation of the Roche folate assay in 2016, folate values were recalculated accordingly for adaptation to results obtained using the present calibration. In both genders, folate concentrations decreased continuously with age, whereas cobalamin concentrations peaked at five years of age and then declined. Teenage females had higher concentrations of cobalamin in the age group 12-17.99 years.
|
|
